Temperature Sensing Cable, Fire Alarm Method and Fire Alarm System

The present disclosure generally relates to the field of fire protection technology, and in particular to a temperature sensing cable, a fire alarm method, and a fire alarm system.

A temperature sensing cable, also known as a linear temperature-sensing fire detector, is a fire detector that responds to the temperature around a certain continuous line. Temperature sensing cables are divided into two types: recoverable and irrecoverable. Among them, the irrecoverable temperature sensing cable consists of two conductors insulated with a thermosensitive material. When the ambient temperature rises to a predetermined action temperature, the temperature sensitive material may adhere, causing short circuit between the two conductors, thereby generating an alarm signal. The recoverable temperature sensing cable, also known as an analog-quantity temperature sensing cable, has a resistance that changes with a temperature. When the change in the resistance reaches a set alarm threshold, the detector sends out an alarm signal. Although these temperature sensing cables each can be used to monitor the operating temperature of a power cable, and send out an alarm signal when the temperature at a certain segment on the power cable is too high, none of them can be relied on to accurately locate the high-temperature segment. In addition, these temperature sensing cables generally have the poor performances of moisture resistance and anti-electromagnetic interference. When these temperature sensing cables are used to monitor power cables, they often cause false alarms due to electromagnetic interference and/or moisture (the power cables are usually arranged in places with high electromagnetic interference and/or humidity).

The content of the background section is only the technology known to the inventor and does not necessarily represent the prior art in the art.

In view of one ore more disadvantages in the prior art, the present disclosure provides a temperature sensing cable, including:

According to an aspect of the present disclosure, the controller is configured to:

According to an aspect of the present disclosure, the first temperature acquisition circuit comprises a first resistor and a second resistor connected in series, and wherein the first resistor is a thermistor, and an acquisition node is provided between the first resistor and the second resistor; and

According to an aspect of the present disclosure, the temperature-sensing control unit further comprises a third resistor, a fourth resistor, a fifth resistor and a differential circuit, and wherein the third resistor is coupled between an upstream end of the first wire and an upstream end of the second wire, the fourth resistor is coupled between the power port and a downstream end of the first wire, the fifth resistor is coupled between a downstream end of the second wire and the ground, and the differential circuit has two input terminals, one of which is coupled to the downstream end of the first wire and the other of which is coupled to the downstream end of the second wire; and

According to an aspect of the present disclosure, the differential circuit is integrated in the controller.

According to an aspect of the present disclosure, the temperature-sensing control unit further comprises a voltage-stabilizing capacitor, one electrode of which is grounded and the other electrode of which is coupled to the power port.

According to an aspect of the present disclosure, the power signal multiplexing cable comprises a third wire and a fourth wire;

According to an aspect of the present disclosure, the first filter circuit comprises a sixth resistor, a filter capacitor and a noise-reduction discharge device, wherein the sixth resistor is connected between the third wire and the power-supply port; one electrode of the filter capacitor is grounded, and the other electrode of the filter capacitor is coupled between the sixth resistor and the power-supply port; and the noise-reduction discharge device has a built-in spike discharge circuit, and is connected between the third wire and the data port.

According to an aspect of the present disclosure, the temperature-sensing control unit further comprises a first diode, which is connected between the third wire and the first filter circuit and is configured to allow a current to flow from the third wire to the first filter circuit.

According to an aspect of the present disclosure, the controller has a built-in second filter circuit, which is coupled to the data port and is configured to filter out an interference signal.

According to an aspect of the present disclosure, the temperature sensing cable further comprises an insulating layer, the power signal multiplexing cable and the temperature sensing lines are embedded in the insulating layer, a plurality of mounting holes are provided on the insulating layer, and the temperature-sensing control units are provided in the mounting holes; and an insulating protective layer is sleeved on outside of the insulating layer, and is arranged along an entire length of the temperature sensing cable.

The present disclosure further provides a fire alarm method, based on the temperature sensing cable described above, the fire alarm method including:

According to an aspect of the present disclosure, the determining a plurality of relevant temperature-sensing control units according to the early warning signal comprises:

According to an aspect of the present disclosure, the determining whether to perform a fire alarm according to the temperature field data information of the plurality of relevant temperature-sensing control units comprises:

According to an aspect of the present disclosure, the first factor A is determined according to the following formula:

According to an aspect of the present disclosure, the second factor is a number of ones exceeding a preset threshold among the rates of change of the first analog quantities of the relevant temperature-sensing control units.

According to an aspect of the present disclosure, the third factor C is determined according to the following formula:

where n is a number of the relevant temperature-sensing control units, MRis the second analog quantity of an i-th relevant temperature-sensing control unit among the plurality of relevant temperature-sensing control units, MRis the second analog quantity of an (i−1)th relevant temperature-sensing control unit among the plurality of relevant temperature-sensing control units, and Mis an environmental reference value.

According to an aspect of the present disclosure, the fourth factor D is determined according to the following formula:

where n is a number of the relevant temperature-sensing control units, and MR/T is the rate of change of the second analog quantity of an i-th relevant temperature-sensing control unit among the plurality of relevant temperature-sensing control units.

The present disclosure further provides a fire alarm system, including:

According to an aspect of the present disclosure, the signal processing unit is configured to:

According to an aspect of the present disclosure, the signal processing unit is configured to:

According to an aspect of the present disclosure, the signal processing unit is configured to: determine the first factor A according to the following formula:

where n is a number of the relevant temperature-sensing control units, MRis the first analog quantity of an i-th relevant temperature-sensing control unit among the plurality of relevant temperature-sensing control units, and MRis the first analog quantity of an (i−1)th relevant temperature-sensing control unit among the plurality of relevant temperature-sensing control units.

According to an aspect of the present disclosure, the second factor is a number of ones exceeding a preset threshold among the rates of change of the first analog quantities of the relevant temperature-sensing control units.

According to an aspect of the present disclosure, the signal processing unit is configured to determine the third factor C according to the following formula:

where n is a number of the relevant temperature-sensing control units, MRis the second analog quantity of an i-th relevant temperature-sensing control unit among the plurality of relevant temperature-sensing control units, MRis the second analog quantity of an (i−1)th relevant temperature-sensing control unit among the plurality of relevant temperature-sensing control units, and Mis an environmental reference value.

According to an aspect of the present disclosure, the signal processing unit is configured to determine the fourth factor D according to the following formula:

where n is a number of the relevant temperature-sensing control units, and MR/T is the rate of change of the second analog quantity of an i-th relevant temperature-sensing control unit among the plurality of relevant temperature-sensing control units.

Compared with the prior art, the embodiment of the present disclosure provides a temperature sensing cable, wherein a controller in a temperature-sensing control unit can sense the change in the temperature nearby through a first temperature acquisition circuit and a second temperature acquisition circuit, and output an early warning signal to provide a high temperature warning (or fire warning). The early warning signal can carry address information of the controller. By determining the position of the controller that sends out the early warning signal, the high temperature point (or firing point) can be accurately located. A first filtering circuit and a power signal multiplexing cable can provide a stable power supply and an amplitude-limited and width-limited signal for the controller, and the controller has a built-in second filtering circuit, which can filter out an interference signal, thereby improving the anti-electromagnetic interference performance of the temperature sensing cable. By embedding the power signal multiplexing cable and the temperature sensing lines into an insulation layer, arranging the temperature-sensing control units in mounting holes on the insulation layer and covering the mounting holes with an insulating protective layer, the moisture-proof performance of the temperature sensing cable can be improved.

The embodiments of the present disclosure further provide a fire alarm method and a fire alarm system, which are implemented based on the above-mentioned temperature sensing cable. By performing a comprehensive judgment on the temperature field data information of multiple relevant temperature-sensing control units, false alarms can be reduced, especially false alarms caused by factors such as electromagnetic interference, humid environment, construction extrusion, local rapid temperature rise.

In the following, only some exemplary embodiments are briefly described. As a person skilled in the art can realize, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present disclosure. Accordingly, the drawings and descriptions are to be regarded as illustrative and not restrictive in nature.

In the description of the present disclosure, it needs to be understood that the orientation or position relations denoted by such terms as “central” “longitudinal” “latitudinal” “length” “width” “thickness” “above” “below” “front” “rear” “left” “right” “vertical” “horizontal” “top” “bottom” “inside” “outside” “clockwise” “counterclockwise” and the like are based on the orientation or position relations as shown in the drawings, and are used only for the purpose of facilitating description of the present disclosure and simplification of the description, instead of indicating or suggesting that the denoted devices or elements must be oriented specifically, or configured or operated in a specific orientation. Thus, such terms should not be construed to limit the present disclosure. In addition, such terms as “first” and “second” are only used for the purpose of description, rather than indicating or suggesting relative importance or implicitly indicating the number of the denoted technical features. Accordingly, features defined with “first” and “second” may, expressly or implicitly, include one or more of the features. In the description of the present disclosure, “plurality” means two or more, unless otherwise defined explicitly and specifically.

In the description of the present disclosure, it needs to be noted that, unless otherwise specified and defined explicitly, such terms as “installation” “coupling” and “connection” should be broadly understood as, for example, fixed connection, detachable connection, or integral connection; or mechanical connection, electrical connection or intercommunication; or direct connection, or indirect connection via an intermediary medium; or internal communication between two elements or interaction between two elements. For those skilled in the art, the specific meanings of such terms herein can be construed in light of the specific circumstances.

Herein, unless otherwise specified and defined explicitly, if a first feature is “on” or “beneath” a second feature, this may cover direct contact between the first and second features, or contact via another feature therebetween, other than the direct contact. Furthermore, if a first feature is “on”, “above”, or “over” a second feature, this may cover the case that the first feature is right above or obliquely above the second feature, or just indicate that the level of the first feature is higher than that of the second feature. If a first feature is “beneath”, “below”, or “under” a second feature, this may cover the case that the first feature is right below or obliquely below the second feature, or just indicate that the level of the first feature is lower than that of the second feature.

The following disclosure provides various different embodiments or examples so as to realize different structures described herein. In order to simplify the disclosure herein, the following will give the description of the parts and arrangements embodied in specific examples. Of course, they are only for the exemplary purpose, not intended to limit the present disclosure. Besides, the present disclosure may repeat a reference number and/or reference letter in different examples, and such repeat is for the purpose of simplification and clarity, which does not represent any relation among various embodiments and/or arrangements as discussed. In addition, the present disclosure provides examples of various specific processes and materials, but those skilled in the art can also be aware of application of other processes and/or use of other materials.

The preferred embodiments of the present disclosure are described below in conjunction with the drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present disclosure and are not used to limit the present disclosure.

shows a principle diagram of a temperature sensing cableaccording to an embodiment of the present disclosure,shows an enlarged view of a portion of, andshows a schematic diagram of a temperature sensing cableaccording to an embodiment of the present disclosure. The following is a detailed description in conjunction with.

As shown in, the temperature sensing cableincludes a power signal multiplexing cable, temperature sensing linesand temperature-sensing control units, wherein the power signal multiplexing cableextends in a first direction and can be used to provide power supply and data communication for the temperature-sensing control units. There are multiple temperature sensing linesand multiple temperature-sensing control units, respectively. The multiple temperature sensing linesare arranged at an interval along a length direction of the power signal multiplexing cable, and the multiple temperature-sensing control unitseach are electrically connected between adjacent temperature sensing lines. That is, the temperature sensing linesand the multiple temperature-sensing control unitsare alternately arranged in sequence and connected to each other in the length direction of the power signal multiplexing cable. The temperature sensing lineincludes a first wire, a second wireand a temperature-sensing material Ra, wherein the temperature-sensing material Ra is connected between the first wireand the second wire. The temperature-sensing material Ra is a conductor, and its resistance value varies with the change of temperature (for example, the higher the temperature, the smaller the resistance value of the temperature-sensing material Ra). The temperature-sensing control unitincludes a controllerand a first temperature acquisition circuit. In addition, adjacent temperature-sensing control unitsand a temperature sensing linelocated therebetween form a second temperature acquisition circuit. The first temperature acquisition circuitand the second temperature acquisition circuitcan both accurately monitor the change of the ambient temperature. Specifically, the controlleris coupled to the power signal multiplexing cable, the first temperature acquisition circuit, and the second temperature acquisition circuit, respectively. The controlleris configured to receive and send signals via the power signal multiplexing cable. The controlleris also configured to obtain a first analog quantity from the first temperature acquisition circuitand a second analog quantity from the second temperature acquisition circuit. The controlleris further configured to output an early warning signal according to the first analog quantity and/or the second analog quantity, wherein both the first analog quantity and the second analog quantity vary with the temperature. Therefore, the early warning signal can accurately reflect the temperature anomaly. By tracing the source of the early warning signal, the high temperature point or potential firing point can be accurately found.

According to one embodiment of the present disclosure, as shown in, the controllercan be configured to output the early warning signal when the first analog quantity reaches a first warning threshold and the second analog quantity is in a first warning interval. The controllercan also be configured to output the early warning signal when the rate of change of the first analog quantity reaches a second warning threshold and the rate of change of the second analog quantity is in a second warning interval. The rate of change of the first analog quantity is defined as the change amount of the first analog quantity in a unit time, and the rate of change of the second analog quantity is defined as the change amount of the second analog quantity in a unit time. The controllercan also be configured to output the early warning signal when the rate of change of the second analog quantity reaches a third warning threshold. The above configurations further enhance the warning capability of the temperature sensing cable, so that the temperature sensing cablecan not only respond to the current temperature state, but also provide early warning for the trend of temperature change, thereby playing a key role in fire prevention and early detection.